Detergent composition



Patented July 24, 1934 DETERGENT COMPOSITION William S. Calcott, PennsGrove, N. J., and George Henry Cheney, Newport, Del., asslgnors to E. I,du Pont de Nemours & Company, Wilmington, Del., a corporation ofDelaware No Drawing.

Application October 23, 1929,

Serial No. 401,971

Claims.

This invention relates to detergent or cleaning compositions, and moreparticularly to such compounds as are suitable for removing oily orgreasy deposits of dirt or rust from metallic sur- 6 faces such as, forexample, the radiators of automobiles.

The prior art describes commercial cleaning compounds which may beroughly divided-into two separate classes, acids, usually with anadditional substance present to prevent the excessive corrosion of theacid upon metal; and alkaline detergents, such as sodium silicate,sodium carbonate, either with or without the addition of rosin orsimilar substances. The cleaning of sheet metal surfaces or simple metalshapes or containers presents no great problems. The cleaning ofautomobile radiators, however, because ofthe function of the radiatorand its proximity to the engine is in operation which does not lenditself readily to the employment of acid cleaning solutions because ofpotential danger to the radiator and delicate parts of the engine. Whenalkaline cleaners are resorted to by garage attendants or mechanics,commercial cleaning preparations or washing soda, borax or lye are mostfrequently used. Mechanical methods, such as blowing out the tubes orwater passages with air and water are frequently employed, probably moreso than the alkaline cleaning compounds, which at best are non tooeffective.

Our invention has for an object the provision of a cleaning compositionor detergent composition which may be used in an aqueous solution andreadily removes dirt and rust deposits on metal surfaces even where, asin automobile radiators, the dirt and corrosion products are gummedtogether with oil and grease. V

A further object is the creation of a composition which is capable of,and a process of, removing dirt, rust and grease from the coolingsystoms of internal combustion engines. Further objects will appear asthis description proceeds.

We accomplish these objects of our invention by the use of a compositionof matter which in one of its broad aspects comprehends the addition ofa wetting-out agent to a detergent, with or without the addition ofanorganic solvent which is immiscible with water.

- In order to establish comparative results for the various compositionsof matter which fall within the contemplation of our invention, we haveevolved the following method of testing: We simulated the conditionswhich exist in a fouled automobile radiator by coating small metal of apaste consisting of iron oxide (F6203) and lubricating grease. Theweight of the deposits was determined by weighing each metal stripbefore and after coating with the paste. The strips were then suspendedin the cleaning fluids, 69 which were to be tested, and the solutionswere boiled for ten minutes. At the end of this time the strips wereremoved, rinsed and air-dried. The loss in weight of the deposits wasobtained by again weighing the strips. A measure of the 5 cleaning powerof the liquid, determined as the percentage loss in weight of thedeposit, was thus obtained for comparison with the cleaning power ofother compositions. According to our method of testing, the loss withwater alone, with water 70 plus a detergent, such as sodium carbonate orwith various prior art commercial cleaners, varies from 4 to 20%, withthe latter percentage the maximum loss obtained by any prior artcomposition. The addition to the detergent solution of even smallamounts of a wetting-cut agent greatly increased the removal of thepaste, as is shown in the following table:

The experiment E in Table 1, above, illustrates the fact that thewetting-out agent by itself possesses no unusual properties in removingthe paste from a metallic surface. It is evident that the greatlyincreased removal of the paste is due to the combined presence of thedetergent and wetting-out agent.

We have found that not only the wetting-out agents appearing in Table 1but all compounds belonging to a class of compounds which may be definedas the sulphonic acid derivative of alkylated aromatic hydrocarbons, andspecifically such hydrocarbons which contain at least two benzenenuclei, are effective wetting-out agents. Our invention contemplates anymember of the class falling within the definition given just above, andembraces other compounds which we have tested and found to be eifective,such as:

l-iso propyl naphthalene-2:4-disodium disulfonate l-4-di-isopropylnaphthalene-Z-sodium sulfonate l-iso-butyl naphthalene-2:4-disodiumdisulfonate 1:4-di-isobutyl naphthalene-2-sodium sulfonate 4-propyldiphenyl-2:4'-disodium disulfonate 4:4'-dipropyl diphenyl-2-sodiumsulfonate 'We have also found that the cleansing action of a detergentand a wetting-out agent is enhancedby the addition to the cleansingsolution of an organic solvent which is immiscible with water. Anyorganic solvent which is immiscible with water falls within thecontemplation of our invention. Examples of the increased cleansingaction obtained by the use of such organic solvents appear in thefollowing Table 2.

(It may be stated that the results given in Table 2 are not exactlycomparable with the results shown in Table 1 because a heavier coatingof paste was employed in all of the work which was tabulated outside ofTable l.)

Tabie II Detergent Wetting agent Solvent Loss Percent 4.0% Ne;PO 0.4%l-isopropyl- None 49.0

naihthaleneso ium suitonote. Do. do 1.0% kerosene 87. 6 Do ..do 1.0%dichlorben- 75.7

zene. Do -.do 1.0% amyl alcohol. 99.4 Do do 1.0% cyclohexanol. 95.8

The action of the wetting-out agent and the immiscible organic solventis not specific to sodium carbonate and trisodium phosphate, but,combined with all classes of salts and alkalis having detergentproperties, serves to produce compositions of matter having remarkablecleaning powers. Examples of such compositions of matter appear in thefollowing Table 3:

It will be understood that the inorganic salts and alkalis listed abovehave been used for the purpose of illustration only, and that otheralkalis and salts having detergent properties fall within thecontemplation of our invention.

We have found that the addition of the wetting-out agent in anyconcentration is beneficial to the cleansing compound or cleansingsolution. We prefer, however, to employ not more than 7.5% ofwetting-out agent, the percentage being based upon the weight of themixture of detergent wetting-out agent and organic solvent when solventwas used. Greater amounts than 7.5%

amount necessary to saturate the water to which it is added has no illeffect, and in fact produces good results, but no better results areproduced than those obtained by increasing the percentage of organicsolvent beyond 20% of the mixture. No particular order need be followedin mixing the materials since the same ultimate mixture will result fromany order of mixing. We have found that generally, however, a somewhatmore homogeneous mass will result if the organic solvent is added last.

We have found that mixtures of salts with one or more wetting-out agentsand one or more solvents in any proportions may be used. Some mixtureswhich we have found to be exceptionally eficient appear in the followingTable 4:

Table 2. V

Salt Wetting agent Solvent 1 75% Na;PO 7.5% l-isopropyl 17.5%dlchlorbennaphthalene 2 zene. sod um sulionate. 2 76% Na;C0a 7.5l-isobutyl napli- 17.5 kerosene.

thalene-2-sodium vs i 1 h 115 diclflo be 37.5 N21200:..-" 'lsopmpy mp rn. 3 thalene-z-sodium acne.

{37.6 N8aPO4.- Mom,- 4 75 NB3P04---- {fife fi e i en e 6 15 fln{ifstitiit It will be understood that the mixtures listed in Table 4have been used for the purpose of illustration only, and that othercombinations fall within the contemplation of our invention.

The composition of matter which we have invented may be used to removeany deposits of dust, dirt or rust which adhere to metallic surfaces.The compounds are unusually effective where the dirt or corrosionproducts are mixed with oil or grease to form pastes or gums which priorart detergent solutions heretofore removed with great difficulty, if atall. Thus, sodium silicate or carbonate solutions of standardconcentrations for detergent purposes removed between 5 and 20% andnever more than 20% of greasy paste from metallic surfaces, whereassolutions formed from the compositions of matter which we have inventedremoved from 80 to of the greasy paste under identical conditions.Automobiles which have been treated by commercial cleaners withouteffect have been put into good running order by the use of ourcompositions of matter. For example, a car of well-known make which wasoverheating badly was treated with a 5% solution of mixture 1, Table 4,at a temperature approximating the boiling point of the solution. Beforetreatment the drain water from the radiator of the car analyzed 0.046%Fe as FezOa, while after'treatment with the above mentioned mixture thedrain water analyzed 0.274% Fe as FezOa. After Washing out the cleaningsolution and filling the radiator with fresh water, a road test at 45 to50 miles an hour failed to show any recurrence of the previous heating.

Although we have shown in this last example the use of a 5% solution ofthe compositions of matter which we have invented, any concentration ofsolution may be employed, depending upon the amount of corrosionproducts and grease present on the metallic surface and the persistencewith which'the corrosion products and grease adhere to the surface. Wehave illustrated the use of a 5% solution to show that solutions ofconcentration aslow as that figure and even lower eifectiv'ely removethe \mdesirable deposits.

As many apparently widely diderent embodiments of this invention may bemade without I departing from the spirit thereof, it is to be understoodthat we do not limit ourselves to the foregoing examples or descriptionsexcept as indicated in the following patent claims:

We claim:

1. A composition of matter, useful in clean-- 3. A composition ofmatter, useful in cleaning metallic surfaces, which comprises about 4parts of an alkali metal carbonate, about 0.4 parts of a sulfonic acidderivative of a propylated naphthalene and about 1 part of an organicsolvent of the group consisting of amvl alcoholand cyclohexanol.

4. A composition of matter, useful in cleaning metallic surfaces, whichcomprises about 4 parts oi sodium carbonate, about 0.4 parts of asulfonic acid derivative of an alkylated naphthalene and about 1 part oian organic solvent of the group consisting of amyl alcohol andcyclohexanol.

5. A composition of matter, useful in cleaning metallic surfaces, whichcomprises about 4 parts sodium carbonate, about 0.4 parts of a sulfonicacid derivative of a propylated naphthalene and about 1 part of anorganic solvent of the group consisting of amyl alcohol andcyclohexanol.

WILLIAM S. CAIBOI'I'. GEORGE HENRY CHENEY.

